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.\" Common Development and Distribution License ("CDDL"), version 1.0.
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.\" 1.0 of the CDDL.
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.\" Copyright 2016 Joyent, Inc.
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.Dd "Jan 13, 2015"
.Dt THRD_CREATE 3C
.Os
.Sh NAME
.Nm thrd_create
.Nd create a thread
.Sh SYNOPSIS
.In threads.h
.Vt "typedef int (*thrd_start_t)(void *);"
.Ft int
.Fo thrd_create
.Fa "thrd_t *thrdp"
.Fa "thrd_start_t func"
.Fa "void *arg"
.Fc
.Sh DESCRIPTION
The
.Fn thrd_create
function creates a new thread of execution inside of the current
process and stores its identifier in
.Fa thrdp .
Each thread operates concurrently within the process.
.Pp
When a thread is created, it begins its execution at the function
.Fa func
with the argument
.Fa arg .
A created thread has access to all global data within a process;
however, it has its own private stack.
Currently 32-bit processes have a default stack of 1 megabyte, while 64-bit
systems have a default stack size of 2 megabytes.
In addition, newly created threads inherit the signal mask of the thread which
created them; however, they do not inherit any pending signals.
.Pp
Once created, a thread will continue to execute until either, it returns
from its initial function, the thread explicitly calls
.Xr thrd_exit 3C ,
or the process itself terminates, such as with a call to
.Xr exit 2 .
When the initial function returns, it behaves as though a call to
.Xr thrd_exit 3C
was made, and, if the thread has not been detached with a call to
.Xr thrd_detach 3C ,
the exit status remains available and the corresponding thread ID will
not be reused until a process calls
.Xr thrd_join 3C .
This is similar to how a parent must call
.Xr wait 3C ,
to clean up a child process that has terminated.
.Pp
For a richer interface interface with more control over aspects of the
newly created thread, such as stack size, stack placement, and the like,
see
.Xr thr_create 3C
and
.Xr pthread_create 3C .
.Sh RETURN VALUES
Upon successful completion, the
.Fn thrd_create
function returns
.Sy thrd_success .
If insufficient memory was available, then
.Sy thrd_nomem
is returned.
Otherwise,
.Sy thrd_error
is returned, indicating that a non-memory related error.
.Sh INTERFACE STABILITY
.Sy Standard
.Sh MT-LEVEL
.Sy MT-Safe
.Sh SEE ALSO
.Xr pthread_create 3C ,
.Xr thr_create 3C ,
.Xr thrd_detach 3C ,
.Xr thrd_join 3C ,
.Xr attributes 7 ,
.Xr threads 7
